Tower Of Cable

Digital: Compressing More Channels, Services Into Your Home

Take a television signal. Squeeze it. Now you have a bunch of TV signals.

That's digital compression. And that's how you're supposed to get the miraculous, 500-cable channels you keep hearing about.

That mind-boggling concept has been bandied about for several years, and cable companies and engineers say it soon could be a reality. Cox Cable expects to have movies-on-demand using compression in 1995, and Newport News Cablevision is planning to introduce a new video-game channel later this year.

"It's a very large step forward," says Dana Coltrin, technical operations manager at Cox Cable and general manager of the company's Cox Fibernet division.

Digital technology makes compression - and a 500-channel world - possible. The technology converts a video signal into a series of ones and zeros that can be stored on a computer. The signal can be decoded and easily converted back into an image after transmission over satellite and cable.

That digitized signal occupies only a fraction of the space needed for the original video signal, so more compressed channels can fit into the same space that one channel traditionally has. How many? Currently, anywhere from four to 10, though the cable industry has touted a number as high as 20.

Inside the home, users will need a converter to unscramble the digital signals and feed them into a TV set.

Digital technology already is in use. Cable companies employ it now to cut satellite space, reducing their costs. Cox has used compression for pay-per-view programming.

The technology has Newport News Cablevision planning a new interactive channel for later this year, says operations manager Bill Moore. The Sega Channel would allow users to play Sega video games at home.

As currently envisioned, customers would get a cartridge from the cable company, plug it into the game at home and hook up the cable outlet. The cable company would send data down, even from games that are not yet on the market. And players would not have to rent games at the video store.

Another possible use for the technology, currently in the talking stages, is a channel that would allow power companies to make meter readings through the TV, rather than in a visit to a house, Moore says.

Those ideas might be only a portent of things to come. Down the road, digital compression means more channels, interactive services and closer links between telephones and cable services.

But Coltrin and Moore point out two things of which viewers might not be aware:

First, they say, the existence of 500 channels does not mean that there will be 500 entertainment possibilities, 500 NBCs or HBOs. More likely, there would be, say, 100 channels through which you could order movies, a bunch of shopping channels and then other channels on which you could talk to your office or a classroom.

"I think what you're going to find is it'll be menu-driven, broken into entertainment, sports, news, shopping," Moore says. "You go into the menu under some heading and there'll be some other heading that you pick from. You'll have the capabilities of buying stuff a la carte."

Of the 500-channel figure, Coltrin says: "Really, it's a metaphorical figure. When we're talking about that in general, we're talking about targeting individual channels to individual homes. If you add all those up, it might total 500. There may be 500, but most of the time they might not have anything on them."

And not everyone will want or need digital compression. Coltrin and Moore both expect cable companies to offer their existing systems, with existing boxes and cables, for a long time to come, to those customers who don't want more than that.

"There may be services in there than people want but they don't want all of them," Moore says. "Finding out what the people want, I think, is the key to the whole thing. Do people want 500 channels? That's hard to say, because I remember 20 years ago people didn't want 36 channels. But now they want more."